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Table of Contents

Introduction

 

Overview

This document is intended to describe the steps required to deploy Joget Workflow v5 Large Enterprise Edition (LEE) in a clustered environment for scalability and redundancy.

Requirements

In order for clustering to work, the Large Enterprise Edition is required. The standard Enterprise Edition will not work due to licensing restrictions. Clustering requires several layers to be prepared and configured:

  • Load Balancers
  • Application Servers
  • Shared File Directory
  • Shared Database

...

 

Architecture

 

There are many ways to design the clustering architecture, but the core concepts will be similar. In this document, the architecture used is as follows:

 

Deployment and Configuration Guide

 

This guide describes the steps required to setup Joget Workflow LEE clustering. The exact steps will depend on the actual products used in each layer.

 

Warning
IMPORTANT: Please note that there is minimal configuration required in Joget Workflow LEE itself, and almost all the work is done on the separate layers so it is vital to ensure that you have sufficient expertise in your chosen products.

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Pre-Deployment Requirements

Before the clustering installation can be done, the following prerequisites are needed: 

Shared file directory

 

Common directory to be accessed by the application servers with read/write permissions. This directory is used to store shared configuration files, system generated files, and uploaded files. Verify that the shared directory is mounted on the application servers and that files can be accessed with read and write permissions.

...

 

Shared database

 

Common database to be accessed by the application servers with permission to select, update, delete, create and alter tables. Verify that the application servers can connect and query the shared database.

 

Application servers

 

Java web application server to be installed and running on each server in the cluster. Verify that each application server has been installed correctly and can be accessed with a web browser.

 

Session replication

...

Session replication to be configured on the application servers and network. Verify that session replication has been configured for each application server and the network.

...

 

Load balancer

 

Load balancer (hardware or software) to be installed and configured to direct traffic for requests beginning with /jw to the application servers. Verify that the load balancer has been installed and configured correctly so that web traffic is directed to the individual application servers.

 

Joget Workflow Clustering Configuration

...

It is important to ensure that the pre-deployment requirements have been verified. Once verified, the Joget Workflow specific steps are as follows:

Datasource Configuration

Configure the datasource properties files in the shared directory

...

Code Block
workflowDriver=com.mysql.jdbc.DriverworkflowUrl=jdbc\:mysql\://host\:port/database_name?characterEncoding\=UTF-8
workflowUser=username
profileName=
workflowPassword=password

 

 

Application Deployment and Configuration

 

Deploy Joget WAR files to the application servers and configure the startup properties to point to the shared directory.

...

Code Block
export JAVA_OPTS="-XX:MaxPermSize=128m -Xmx1024M -Dwflow.home=/shared_directory_path"

 

License Activation

Activate license for each server. Each server has a unique system key and requires a separate license activation.

  1. For each of the application servers, use the browser to directly access the Joget web console bypassing the load balancer e.g. {+}http://server1:8080/jw/web/console/home+
  2. Request for license and activate it using the link in the web console footer.

 

...



Post-Deployment Testing

 

Once the pre-deployment and clustering configuration has been done, the testing is a matter of using a web browser to access the load balancer. 

 

Sample Installation and Configuration

...

Warning
IMPORTANT: Please note that this is not a comprehensive guide and does not cover production-level requirements e.g. user permissions, network and database security, etc. Please ensure that these are covered by your system, network and database administrators.

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Create a Shared File Directory

...

In the file server, install the NFS server

 

Code Block
sudo apt-get install portmap nfs-kernel-server

Create shared directory and set permission

 

Code Block
sudo mkdir -p /export/wflow
sudo chown nobody:nogroup /export/wflow

Configure NFS to export the shared directory, edit /etc/exports to export the directory to the local 192.168.1.0 subnetwork with your favourite editor

 

Code Block
sudo vim /etc/exports 

...

Export the shares and restart NFS service

 

Code Block
sudo exportfs -ra
sudo service nfs-kernel-server restart 

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Mount the Shared Directory in the Application Servers

 

...

In the application servers, install the NFS client 

Code Block
apt-get install nfs-common

Create new directory /opt/joget/shared/wflow to mount the shared directory and set the directory permissions

 

Code Block
sudo mkdir -p /opt/joget/shared/wflow
sudo chmod 777 /opt/joget/shared/wflow

Mount the shared directory. 

Code Block
sudo mount -t nfs wflow:/export/wflow /opt/joget/shared/wflow

Test read-write permissions to confirm that the directory sharing works.

 

Code Block
echo test123 > /opt/joget/shared/wflow/test.txt

...

Install MySQL (https://help.ubuntu.com/14.04/serverguide/mysql.html)  

Code Block
sudo apt-get install mysql-server

Create a database called jwedb accessible to the application servers.

 

Code Block
mysql -u root 

Run the following MySQL commands to create a blank database

...

Populate the newly created database with the Joget database schema

 

Code Block
mysql -uroot jwedb < /path/to/jwdb-mysql.sql

 

Configure database permissions 

Code Block
mysql -u root 

Run the following MySQL commands to grant permissions to user joget and password joget

...

Configure MySQL to listen to database connections from remote hosts. Edit the my.cnf file with your favourite editor 

Code Block
sudo vim /etc/mysql/my.cnf 

...

Code Block
sudo service mysql restart

...

In the application server, test a remote connection to the database server database_host

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Deploy Application Servers

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Install Apache Tomcat on each of the application servers. In each application server, run the following to extract tomcat into /opt/joget:

 

Code Block
sudo mkdir -p /opt/joget/
sudo tar xvfz apache-tomcat-8.0.20.tar.gz /opt/joget/

Start each application server

 

Code Block
sudo cd /opt/joget/apache-tomcat-8.0.20
sudo ./bin/catalina.sh start

Open a web browser and access each server to confirm that http://server:8080/jw

 

 

Configure Application Server Session Replication

 

Configure Tomcat for clustering by editing apache-tomcat-8.0.20/conf/server.xml. Add jvmRoute="node01" to the Engine tag and uncomment the Cluster tag.

 

Code Block
<Engine name="Catalina" defaultHost="localhost" jvmRoute="node01">
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>

Configure local domain IP. Verify that the local server name resolves to the IP and not 127.0.1.1. Assuming the server name is server1 and the IP is 192.168.1.10, edit /etc/hosts and set: 

Code Block
192.168.1.10 server1

Verify multicast is enabled between the application servers by running ifconfig and look for MULTICAST. Try http://blogs.agilefaqs.com/2009/11/08/enabling-multicast-on-your-macos-unix/ if there are issues. 

Restart the Tomcat servers.

 

Code Block
sudo cd /opt/joget/apache-tomcat-8.0.20
sudo ./bin/catalina.sh stop
sudo ./bin/catalina.sh start

Verify session replication working between the application servers. The catalina.out log file in apache-tomcat-8.0.20/logs should show something similar to: 

Code Block
INFO: Starting clustering manager at localhost#/jw
Jan 17, 2016 11:21:32 AM org.apache.catalina.ha.session.DeltaManager getAllClusterSessions
INFO: Manager [localhost#/jw], requesting session state from org.apache.catalina.tribes.membership.MemberImpl[tcp://{127, 0, 0, 1}:4001,{127, 0, 0, 1},4001, alive=55733886, securePort=-1, UDP Port=-1, id={-57 118 -98 -98 110 -38 64 -68 -74 -25 -29 101 46 103 5 -48 }, payload={}, command={}, domain={}, ]. This operation will timeout if no session state has been received within 60 seconds.
Jan 17, 2016 11:21:32 AM org.apache.catalina.ha.session.DeltaManager waitForSendAllSessions
INFO: Manager [localhost#/jw]; session state send at 1/17/16 11:21 AM received in 104 ms.

More information on Tomcat clustering is at http://tomcat.apache.org/tomcat-8.0-doc/cluster-howto.html

 

Configure Load Balancer

In the load balancer server, install Apache HTTP Server 

Code Block
sudo apt-get install apache2

Install proxy and balancer modules  

Code Block
sudo a2enmod headers proxy proxy_balancer proxy_http

Configure a new site with the proxy and balancer modules. Create a new file in /etc/apache2/sites-available, named jwsite

 

Code Block
sudo vim /etc/apache2/sites-available/jwsite.conf 

Add

...

the

...

contents

Code Block
 
NameVirtualHost *
<VirtualHost *>
	DocumentRoot "/var/www/jwsite" 
	ServerName localhost
	ServerAdmin support@mycompany.com
	DirectoryIndex index.html index.htm 
	<Proxy balancer://cluster>
		BalancerMember http://server1:8080 route=node01
		BalancerMember http://server2:8080 route=node02
		Order deny,allow
		Allow from all
	</Proxy> 
	ProxyPreserveHost On
	ProxyPass /jw balancer://cluster/jw stickysession=JSESSIONID
	ProxyPassReverse /jw balancer://cluster/jw
</VirtualHost>

Enable the new site and restart Apache 

Code Block
sudo a2ensite jwsite
sudo service apache2 reload

...